To study the effects of air pollutants on large perennial plants, two designs of large, open-top chambers were tested in wind runnel studies and subsequent field trials. Flow visualization of air patterns in the wind tunnel showed that a frustum and inner baffle plate covering 50% of the top surface provided the best exclusion capabilities. This was quantified by measurement of pollutant distribution in scale models. Prototype chambers were erected around grape (Vitus sp.) vines in a commercial vineyard and evaluated over two growing seasons. Exclusion efficiencies of 80 to 95% were found during the test period. The rain shadow caused by the frustum was significant with losses greatest near the walls. The average increase in leaf temperature between ambient and within the chamber was 2.5 °C. Light intensity was reduced 14 and 22% in the circular and rectangular chamber, respectively. Although there is some modification of the plant environment, the chambers provide a suitable environment during the growing season for air pollution studies with large perennial plants. Research support provided partially by the Niagara Mohawk Power Corporation, Syracuse, NY.